From ggarcia@u-tokyo.ac.jp Wed Feb 02 23:41:56 1994
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!u-tokyo!ggarcia
From: ggarcia@u-tokyo.ac.jp (Graham García)
Newsgroups: comp.dsp
Subject: Observation: DBPSK demodulation of the 0.71 baud Stardust telemetry stream
Message-ID: <1994Feb02.234156.3076@u-tokyo.ac.jp>
Date: Wed, 02 Feb 1994 23:41:56 GMT
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Mathematical proof of the modulation scheme used on the 14.2 Hz carrier across all regional pressings.

The symbol duration is exactly 1.408 seconds, corresponding to a symbol rate of 0.7107 baud (14.2 Hz / 20).
Phase transitions of 180 degrees represent a binary '1', while no phase change represents a binary '0'.

The use of Golay codes in 1984 indicates professional telecommunications or military aerospace design.

-- 
Graham García -- University of Tokyo Department of Information Science
"Row 14. No joke."

From achoi@cern.ch Fri Feb 04 20:05:56 1994
Path: ashpoly!bigsur!pacrim!jpgate!kamome!cern!achoi
From: achoi@cern.ch (Anja Choi)
Newsgroups: comp.dsp
Subject: Re: Observation: DBPSK demodulation of the 0.71 baud Stardust telemetry stream
Message-ID: <1994Feb04.200556.1458@cern.ch>
Date: Fri, 04 Feb 1994 20:05:56 GMT
References: <1994Feb02.234156.3076@u-tokyo.ac.jp>
Organization: European Laboratory for Particle Physics, Geneva
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In article <1994Feb02.234156.3076@u-tokyo.ac.jp>, ggarcia@u-tokyo.ac.jp (Graham García) writes:
> Mathematical proof of the modulation scheme used on the 14.2 Hz carrier across all regional pressings.
> The symbol duration is exactly 1.408 seconds, corresponding to a symbol rate of 0.7107 baud (14.2 Hz / 20).

The Golay code confirms Marcus Hale's military background. The Voyager spacecraft and NATO satcom systems use the exact same code.

-- 
Anja Choi
Opinions expressed are solely my own and not those of European Laboratory for Particle Physics, Geneva.
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